For years, it has been customary practice in fighting fires for firefighters to carry water back packs and water hand pumps and use them at the fire site. The back pack is filled with water from any readily available source such as a creek, melting snow, puddles, or the like, and the water is carried on the back of the firefighter to the fire site. At the site, the firefighter directs a stream of water at the fire by operating a hand pump which is attached to the back pack.
Studies conducted under firefighting conditions in North America and Australia have indicated that firefighters when engaged in fighting a fire suffer from premature fatigue and very high heartbeat rates. Electrocardiograms taken of firefighters operating under these conditions have demonstrated that their heartbeats are so high that they experience premature fatigue. An aggravating factor is that substantial body heat is lost from the kidneys and lower back area into the cold water carried in the backpack.
Another difficulty with conventional waterproof water backpacks and hand pumps is that they do not permit perspiration to escape from the back of the firefighter. It has been learned that inhibiting evaporation of perspiration from the back of the firefighter leads directly to premature fatigue. Thus, the firefighter tires prematurely and cannot continue to fight the fire. This is a serious problem with most forest fire situations because usually there is a shortage of men available to fight the forest fire and premature fatigue reduces further the number of men available.
A third problem, which is mechanical in nature, is that in many cases the water that is used to fill the backpack is not clean but is full of dirt, debris and the like. This material accumulates in the backpack and often blocks the water inlet into the waterpump. In such cases, the water pump must be dismantled and the blocked inlet cleaned of debris before the unit can be used again. This causes down-time of equipment at the fire site.
The applicant is aware of U.S. Pat. No. 1,902,548, F. F. Fenwick, Jr., Mar. 21, 1933, which discloses a flexible collapsible water backpack and hand pump for use in fighting forest fires and the like. The backpack is constructed so that it can be carried on the back in a folded condition to form a compartment for holding water. The backpack is carried on the back by means of a shoulder strap and girth harness.
U.S. Pat. No. 1,953,331, granted Apr. 3, 1934, J. Armstrong, disclose a water backpack design which can be carried on the back of a pack animal. A series of the packs can be carried on the backs of a proportionate number of pack animals and connected together in series.